An outline of the approach

The basic approach to the analysis is either to use a linear regression of offspring phenotype on parental phenotype, which as we'll see estimates $h^2_n$, or to use a nested analysis of variance. One of the most complete designs is a full-sib, half-sib design in which each male sires offspring from several dams but each dam mates with only one sire.

The offspring of a single dam are full-sibs (they are nested within dams). Differences among the offspring of dams indicates that there are differences in maternal ``genotype'' in the trait being measured.²

The offspring of different dams mated to a single sire are half-sibs. Differences among the offspring of sires indicates that thee are differences in paternal ``genotype'' in the trait being measured.³

This design has the advantage that it allows both additive and dominance components of the genetic variance to be estimated.